1. Field of the Invention
This invention relates to process for producing a photoconductive member having sensitivity to electromagnetic waves such as light [herein used in a broad sense, including ultraviolet rays, visible light, infrared rays, X-rays, gamma-rays and the like] and a device for producing the same. More particularly, it pertains to a continuous process for producing a photoconductive member which comprises practicing formation of a thin photoconductive film while heating a support as in the CVD (chemical vapor deposition) process or the plasma CVD process and a device for producing the same.
2. Description of the Prior Arts
Photoconductive materials, which constitutes image forming members for electrophotography in solid state image pick-up devices or in the field of image formation, or photoconductive layers in manuscript reading devices, are required to have a high sensitivity, a high SN ratio [photocurrent (I.sub.p)/ Dark current (I.sub.d)], spectral characteristics matching to those of electromagnetic waves to be irradiated, a rapid response to light, a desired dark resistance value as well as lack of danger to human bodies during usage. Further, in a solid state image pick-up device, it is also required that the residual image should easily be treated within a predetermined time. In particular, in case of an image forming member for electrophotography to be assembled in an electrophotographic device to be used in an office as office apparatus, the aforesaid safety characteristic is very important.
From the standpoint as mentioned above, amorphous silicon [hereinafter referred to as a-Si] has recently attracted attention as a photoconductive material. For example, German Laid-Open Patent Publication No. 2746967 and 2855718 disclose applications of a-Si for use in image forming members for electrophotography, and German Laid-Open Patent Publication No. 2933411 an application of a-Si for use in a photoelectric conversion reading device.
The most primitive process among the processes for producing such photoconductive materials and the device for producing the same is the batch type in which the three steps of heating, forming the photoconductive layer and cooling are conducted in a single chamber. However, this process is not practical, because it is inefficient as the industrial production system. There is also a semi-batch type, in which either two continuous steps of heating, reaction and cooling are practiced in one chamber. This process also involves the same problems as in the batch type.
On the other hand, the continuous three chamber type is also known, in which the three steps of heating, reaction and cooling are practiced in three different chambers. However, in this continuous production process and the device for production thereof, since the heating chamber is opened whenever supports are conveyed into the chamber, the loss in heating energy is great. In addition, there is also the problem that the volume of the air to be discharged and leaked was great.